Combination drill-bit and drill-shank.



G. A. HUMASON.

COMBINATION DRILL BIT AND DRILL SHANK.

APPLICATION FILED MAR 19. I918.

Patented Dec. 30, 1919.

UNITED STATES PATENT oEEIoE.

GRANVILLE A. HUMASON, OF SHREVEPORT, LOUISIANA, ASSIGNOR 0F ONE-THIRD TOEDWARD B. BIERCE AND ONE-THIRD T0 JOHN W. PARKER, BOTH OF HARRIS COUNTY,

TEXAS.

COMBINATION DRILL-BIT 1 AND DRILL-SHANK.

To all whom it may concern:

Be it known that I, GRANVILLE A. HUMA- SON, a citizen of the UnitedStates, residing at Shreveport, in the parish of Caddo and State ofLouisiana, have invented certain new and useful Improvements inCombination Drill-Bits and Drill-Shanks, of which the following is aspecification.

This invention relates to new and useful improvements in the combinationdrill bit and drill shank.

The object of the invention is to provide a drill bit in combinationwith a drill shank by means of which the bit may be securely attached toa drill stem, in such a manner as to prevent the detachment of the bitfrom the stem while down in the bore.

In drilling wells by the rotary process, a drill stem is employed whichis rotated by the rotary and to the lower end of which a bit is attachedthrough the medium of a drill shank. As now constructed, the lower endof the stem is threaded into the upper end of the drill shank and theshank of the bit is threaded into the lower end of the drill shank. Indrilling through hard strata, the threads of the bit shank and thecorresponding threads of the drill shank are subjected to great strain,and furthermore the bit must be often removed and sharpened andreplaced, consequently said threads soon become battered and worn, sothat the bit he comes loose in the drill shank and when the 'stem isrotated backwardly, or when it is being pulled from the bore, the bitoften drops ofi and remains in the bottom of the bore, thus interferingwith and sometimes entirely stopping the process of drilling.

It is the object of this invention to provide a drill shank and meansfor securing the bit thereto wherebysaid bit will be securely fastenedto the stem, and there will be no liability of its becoming detachedtherefrom.

With the above and other objects in view, the invention has particularrelation to cer tain novel features of construction, arrangement ofparts and use, an example of which is given in this specification andillustrated in the accompanying drawin s, wherein Figure 1,- 1s a sideelevation of a drill shown partially in section, taken on the line 1 -'1of Fig. 3.

Specification of Letters Patent.

Patented Dec. 30, 1919.

Application filed March 19, 1918. Serial No. 223,318.

Fig. 2, is a fragmentary side elevation thereof,

Fig. 3, is a transverse sectional view taken on the line 3-3 of Fig. 2,

Fig. 4, is a side view of a detachable blade employed and Fig. 5 is asection on the line 5-5 of Fig. 1.

Referring now more particularly to the drawings wherein like numerals ofreference designate similar parts in each of the figures, the numeral 1,refers to a drill stem, the lower end of which is threaded into theupper end of the drill shank 2. The lower end of this shank is enlargedforming the annular shoulder 3, and the enlarged head 4, said head beingprovided with a transverse tapering mortise 5. The numeral 6 refers to asleeve which is fitted over the drill shank 2, the upper end of which isreduced,

forming an internal annular rim 7, which rests upon the shoulder 3. Thenumeral 8 refers to a drill bit having the externally threaded shank 9,which is screwed into the lower end of said sleeve. The sleeve proj ectsa sufiicient distance below the head 4 to permit this. Integral with andupstanding from, the shank, is a wedge shaped tenon 10, which fits intothe mortise 5 and locks the bit against rotation relative to the shank.

In assembling the bit and shank, the tenon 10 is inserted up into themortise 5, and the sleeve 6, then fitted over said shank and screwedonto the shank 9 of the bit,

and the flange 7 seats on the shoulder 3.

The ordinary fish-tailed bit, usually has I only two blades, butadditional blades may be provided when it is so desired. In the drawing,the detachable blades 11 are shown. These blades are fitted into thevertical'side slots 12, of the bit, and the-shank sections thereof, areprovided with threads 13, to correspond with the threads of the shank 9.These blades 11 are provided with tenons 14 corresponding in shape tothe tenon 10 of the bit, and which fit into the radiating mortises 15,of the head 1 and corresponding slots in the shank 9. When thedetachable blades 11 are used, they are fitted into position before thesleeve 6 is screwed in place, and the said sleeve is then screwed overthe u per ends thereof, and they are thereby loc ed securely in thegrooves 12. In case of hard drilling, should the tenons 10 and 14 becomebroken ofi', the sleeve 6 will still secure the bit against detachmentfrom the shank 2, so that there will be no liability of said bitbecoming lost in the bore.

Water passageways 16, 16 are provided down through the shank 2, andthrough the tenon, fitted into said mortise, said bit eeaaov havingopposing vertical grooves and said shank being provided with lateralmortises alined with said grooves, detachable blades 'fitted into saidgrooves and whose upper ends are formed into tenons which fit into saidalined mortises, and a sleeve fitted over said shank and secured ontosaid bit, said sleeve locking said tenons in their. respective mortises.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

GRANVILLE A. HUMASON; Witnesses:

E.V. HARDWAY, E. B. BIERCE.

